Telephone switch-board



(No Model.)

T. W. LANE.

TELEPHONE SWITCH BOARD. No. 245,515. Patented Aug. 9,1881.

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UNITED STATES PATENT OFFICE.

THOMAS W. LANE, OF BOSTON, ASSIGNOR TO HIMSELF AND CHARLES WILLIAMS, JR, OF SOMERVILLE, MASSACHUSETTS.

TELEPHONE SWlTCH-BOARD.

SPECIFICATION forming part of Letters Patent No. 245,515, dated August 9, 1881.

Application filed June 27, 1881. (No model.)

To all whom tt may concern Be it known that I, THOMAS W. LANE, of Boston, in the county of Sufi'olk and State of Massachusetts, have i nvented certain Improvements in Telephone Switch-Boards, of which the following is a specification.

This invention relates to that class of telephone switch-boards in which the line-circuit strips are provided with springs adapted to bear with a yielding pressure against plugs inserted through perforations in the insulated connecting strips which cross the board at right angles with the line-circuit strips.

Heretofore in this class of switch-boardsthe springs of the line-circuit strips have been so arranged that each plug receives the pressure of but one spring directed against one side of the plug.

My invention has for its object to so arrange said springs that each plug shall receive the pressure of two springs bearing on opposite sides, so that a more reliable and positive contact will be maintained, and one less liable to be accidentally broken than in switch-boards heretofore used.

To this end my invention consists in the arrangement of springs, which I will now proceed to describe and claim.

Ofthe accompanying drawings, forming part of this specification, Figure lrepresents a view of the back side of a switch-board embodying my invention. Fig. 2 represents a section on line 00 m, Fig. .l.

The same letters indicate the same parts in all the figures.

In the drawings, a represents a switch-board, having on its front side the parallel connecting-strips b b, and on its opposite side the linecircuit strips 0 0, arranged substantially at right angles with the line-circuit strips 1).

d d are perforations in the connecting-strips 1/, extending also through the board, and adapted to receiy e movable plugs e.

s 8 represent contact-sprin gs attached to the back of the switch-board a, arranged in pairs, and connected with the line-circuit strips 0, as shown, the springs of each pair being connected with the same line-circuit strip. The springs of each pair are arranged to normally sure an effectual connection between the linecircuit and the connecting-strip through the medium of the plugs, the latter being so supported by the springs that they cannot readily be displaced. In case either spring of a pair becomes broken, the other spring, being connected to the same line-circuit strip, maintains the desired connection.

I prefer to connect each spring with the adjacent spring of the next pair by forming the two springs from a single piece of metal, as shown, or otherwise, so that all the springs of each line-circuit strip will be connected independently of the line-circuit strip. The linecircuit strips are normally connected to a ground-strip, as usual, and the operation of connecting any two of the line-circuits is performed in the usual manner.

Having thus described my invention, I claim- In a switch-board having line-circuit strips, connecting-strips, and perforations extending through said strips and the boa-rd,for the connecting-plugs, all arranged as described, the contact-springs s 8, connected with the linecircuit strips, and arranged in pairs, each pair coinciding with one of said perforations, and

adapted to grasp a plug inserted therein, the

springs of each pair pressing against opposite sides of the plug, as set forth.

In testimony whereof I have signed my name to this specification, in the presence of two subscribing witnesses, this 23d day of June, A. D. 1881.

THOMAS 7. LANE.

Witnesses:

G. F. BROWN, 11. G. WADLIN. 

